The present disclosure relates generally to wireless communications, and more specifically to reducing hypothesis searching for multi-panel precoder selection.
Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-OFDM (DFT-S-OFDM). A wireless multiple-access communications system may include a number of base stations or network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE).
In 5G wireless communications, a base station (e.g., a gNodeB or gNB) may be in communication with a UE. The UE may provide the gNB with a precoding matrix indicator (PMI) report that indicates estimated channel characteristics for a channel between the gNB and the UE. The PMI report defines one or more grouping co-phase factors that are based on precoder indexes the UE calculated for the channel estimate. The gNB can use the information in the PMI report to adjust transmission parameters for subsequent transmissions to the UE. However, some gNBs or UEs may have one or two dimensional multi-panel antenna arrays. Based on these antenna arrays as well as a rank and a configuration mode of the gNB, there may be a large number of precoder hypothesis to calculate for the channel estimate. Calculating channel capacities for so many precoder hypotheses can be very costly in time, processing speed, and power.